I am starting this topic about GHK-cu because I don't see any discussion about it here, and it fits the subject of the forum as a "natural" (endogenous and bioidentical) hair loss treatment. I have used it on and off for decades, along with minoxidil, and have reviewed internet discussions about it, and have read a number of scientific articles and studies. As a disclaimer, I am not any kind of authority and do not recommend that anyone else follow my actions or examples as hair loss remedies for themselves.

Based on my research and experience, I have a number of ideas and theories about GHK-cu:

1) In terms of mechanisms of action, there is little overlap between GHK-cu and minoxidil. GHK-cu may cause hair regrowth primarily as a side effect of restoring the structure of damaged skin, and lengthening the hair growth cycle, while minoxidil directly increases hair growth and speeds up the hair follicle cycles. As a result, GHK-cu takes much longer to work (months or years) while minoxidil may start working in weeks. The two agents may complement each other since they have orthogonal mechanisms of action, but it's possible that GHK-cu, given sufficient time, may perform as well as minoxidil while providing additional benefits of skin and subcutaneous tissue restoration. Minoxidil, over time, may have negative effects on skin health (e.g. possible thinning of skin) although the evidence of this is weak. In summary, GHK-cu may be more of a long-term hair loss solution, while minoxidil may be more of a short term solution.

2) Regarding what I consider to be myths about GHK-cu: I have found no published evidence that GHK-cu inhibits DHT or causes any other endocrine disruption. I have seen some speculation about free cu2+ and resulting ROS, but in that case hormone disruption would be the least of your worries. If the complex remains stable the copper should remain bound. I have seen no evidence of copper toxicity from dermal exposure, and some study results to the contrary. (In any case, risk of free copper can be reduced by an excess of GHK as Loren Pickart has done in some of his human systemic studies). I have not seen personal or scientific evidence of skin damage ("the uglies") at any concentration but I have also avoided all commercial preparations and "copper peptides" containing mixed peptides or copper salts. Another myth has to do with concentration. Commercial preparations use far lower concentrations than what many people on the internet are recommending (including HairEvo). Some studies have used nanomolar concentrations. This suggests that the vehicle and skin penetration are far more important than concentration. In my own experience, I have seen results with concentrations as low as .2%, and I think I can go lower yet.

3) For me GHK-cu has done what years of minoxidil has not done, stop or reverse temple hairline loss. I think minixidil slowed down the loss rate, but it did not stop or reverse it as GHK-cu seems to have done. This is based on about 2 years of usage.

4) I have tried three related peptides: GHK-cu:1, GHK-cu:2 and AHK-cu, and don't see much difference between them in terms of results. GHK-cu:2 occurs naturally, and may reduce theoretical risk of copper exposure, but it easily complexes and decomplexes between GHK and GHK-cu:1 and is more difficult to use with some vehicles. AHK-cu has a longer half life but as a synthetic derivative may sacrifice some of the benefits of GHK, and may have unknown side effects (as such derivatives tend to do). It also has far less human or animal testing and research history behind it.

5) Using GHK-cu, I have focused largely on skin penetration and have experimented with several vehicles, including water, ETOH and PG in various combinations. I have not seen much difference between them, but have not been very systematic either. I suspect the high concentrations I was using (up to 2%) minimized any differences in the vehicles. I have not been using lower concentrations long enough to tell if there is a big difference between vehicles. I have avoided solvents like DMSO due to the risk.

6) On the subject of skin restoration, there is evidence that GHK-cu reverses fibrosis (scarring) and stimulates stem cells and growth factors. All these functions together suggest that GHK-cu may reverse balding in areas previously thought to be unable to grow hair. I have not used it consistently enough or long enough to find out, and my worst hair loss areas still have follicles, so I am probably not a good candidate to test this theory. If it does work on fibrosis scalp areas, I think it may require a year or more to repair the skin.

7) Cost and quality remain big issues with GHK-cu. HairEvo's product seems to have the best non-bulk price, but based on smell and taste it seems to be high in acetate, which may indicate the presence of other excipients and/or high water content. In addition, the acetic acid taste overpowers the "normal" GHK taste of GHK-cu from other suppliers, which is a slightly sweet metallic taste. The power texture and color look right, although there is some clumping. The rate of dissolution in various solvents seem correct. I can't rule out some degree of product decomposition although it is usually a stable compound which stores well. Apparently acetate is common in cosmetic grade GHK-cu, but in my experience, it is undetectable in product from other sources.

Regarding supplements, I am currently experimenting with pregnenolone on the theory that endocrine balance is critical for skin health, and GHK-cu may not do much good for the scalp and hair if hormones that maintain skin as an organ are deficient in pregnenolone and its metabolites. (This applies to aging persons like myself.) I have taken it orally and as a topical (ETOH or oil). I can't report any obvious positive results. (FWIW it works as a powerful anti-itch remedy.) I've also taken a number of aminos, vitamins and minerals but have no idea what I'm doing, nor any idea whether they are doing my hair any good.

Final note: years ago, when GHK-cu was still "new," there was much discussion but the excitement seems to have died off, and not much is heard about it these days. My theory is that people heard it was equivalent to minoxidil and tried it, and when it didn't work in 6 weeks they moved on to the next exciting new thing. They may not realize that GHK-cu is nothing like minoxidil, and forget that aging and MPB occur over years and decades, not weeks or months. I think people were basing their actions mainly on the hype and not on the science. I hope this helps somebody, and I welcome any questions or correction of facts.